funcnode.cc

   1 #include "action.h"
   2 #include "history.h"
   3 #include "funcnode.h"
   4 #include "funcinst.h"
   5 #include "predicate.h"
   6 #include "concretepredicate.h"
   7
   8 #include "model.h"
   9 #include <cmath>
  10
  11 FuncNode::FuncNode(ModelHistory * history) :
  12         history(history),
  13         exit_count(0),
  14         inst_counter(1),
  15         marker(1),
  16         thrd_marker(),
  17         func_inst_map(),
  18         inst_list(),
  19         entry_insts(),
  20         thrd_inst_pred_map(),
  21         thrd_inst_id_map(),
  22         thrd_loc_inst_map(),
  23         thrd_predicate_tree_position(),
  24         thrd_predicate_trace(),
  25         failed_predicates(),
  26         edge_table(32),
  27         out_edges()
  28 {
  29         predicate_tree_entry = new Predicate(NULL, true);
  30         predicate_tree_entry->add_predicate_expr(NOPREDICATE, NULL, true);
  31
  32         predicate_tree_exit = new Predicate(NULL, false, true);
  33         predicate_tree_exit->set_depth(MAX_DEPTH);
  34
  35         /* Snapshot data structures below */
  36         read_locations = new loc_set_t();
  37         write_locations = new loc_set_t();
  38         val_loc_map = new HashTable<uint64_t, loc_set_t *, uint64_t, 0, snapshot_malloc, snapshot_calloc, snapshot_free, int64_hash>();
  39         loc_may_equal_map = new HashTable<void *, loc_set_t *, uintptr_t, 0>();
  40
  41         //values_may_read_from = new value_set_t();
  42 }
  43
  44 /* Reallocate snapshotted memories when new executions start */
  45 void FuncNode::set_new_exec_flag()
  46 {
  47         read_locations = new loc_set_t();
  48         write_locations = new loc_set_t();
  49         val_loc_map = new HashTable<uint64_t, loc_set_t *, uint64_t, 0, snapshot_malloc, snapshot_calloc, snapshot_free, int64_hash>();
  50         loc_may_equal_map = new HashTable<void *, loc_set_t *, uintptr_t, 0>();
  51
  52         //values_may_read_from = new value_set_t();
  53 }
  54
  55 /* Check whether FuncInst with the same type, position, and location
  56  * as act has been added to func_inst_map or not. If not, add it.
  57  */
  58 void FuncNode::add_inst(ModelAction *act)
  59 {
  60         ASSERT(act);
  61         const char * position = act->get_position();
  62
  63         /* THREAD* actions, ATOMIC_LOCK, ATOMIC_TRYLOCK, and ATOMIC_UNLOCK
  64          * actions are not tagged with their source line numbers
  65          */
  66         if (position == NULL)
  67                 return;
  68
  69         FuncInst * func_inst = func_inst_map.get(position);
  70
  71         /* This position has not been inserted into hashtable before */
  72         if (func_inst == NULL) {
  73                 func_inst = create_new_inst(act);
  74                 func_inst_map.put(position, func_inst);
  75                 return;
  76         }
  77
  78         /* Volatile variables that use ++ or -- syntax may result in read and write actions with the same position */
  79         if (func_inst->get_type() != act->get_type()) {
  80                 FuncInst * collision_inst = func_inst->search_in_collision(act);
  81
  82                 if (collision_inst == NULL) {
  83                         collision_inst = create_new_inst(act);
  84                         func_inst->add_to_collision(collision_inst);
  85                         return;
  86                 } else {
  87                         func_inst = collision_inst;
  88                 }
  89         }
  90
  91         ASSERT(func_inst->get_type() == act->get_type());
  92         int curr_execution_number = model->get_execution_number();
  93
  94         /* Reset locations when new executions start */
  95         if (func_inst->get_execution_number() != curr_execution_number) {
  96                 func_inst->set_location(act->get_location());
  97                 func_inst->set_execution_number(curr_execution_number);
  98         }
  99
 100         /* Mark the memory location of such inst as not unique */
 101         if (func_inst->get_location() != act->get_location())
 102                 func_inst->not_single_location();
 103 }
 104
 105 FuncInst * FuncNode::create_new_inst(ModelAction * act)
 106 {
 107         FuncInst * func_inst = new FuncInst(act, this);
 108         int exec_num = model->get_execution_number();
 109         func_inst->set_execution_number(exec_num);
 110
 111         inst_list.push_back(func_inst);
 112
 113         return func_inst;
 114 }
 115
 116
 117 /* Get the FuncInst with the same type, position, and location
 118  * as act
 119  *
 120  * @return FuncInst with the same type, position, and location as act */
 121 FuncInst * FuncNode::get_inst(ModelAction *act)
 122 {
 123         ASSERT(act);
 124         const char * position = act->get_position();
 125
 126         /* THREAD* actions, ATOMIC_LOCK, ATOMIC_TRYLOCK, and ATOMIC_UNLOCK
 127          * actions are not tagged with their source line numbers
 128          */
 129         if (position == NULL)
 130                 return NULL;
 131
 132         FuncInst * inst = func_inst_map.get(position);
 133         if (inst == NULL)
 134                 return NULL;
 135
 136         action_type inst_type = inst->get_type();
 137         action_type act_type = act->get_type();
 138
 139         if (inst_type == act_type) {
 140                 return inst;
 141         }
 142         /* RMWRCAS actions are converted to RMW or READ actions */
 143         else if (inst_type == ATOMIC_RMWRCAS &&
 144                                          (act_type == ATOMIC_RMW || act_type == ATOMIC_READ)) {
 145                 return inst;
 146         }
 147         /* Return the FuncInst in the collision list */
 148         else {
 149                 return inst->search_in_collision(act);
 150         }
 151 }
 152
 153 void FuncNode::add_entry_inst(FuncInst * inst)
 154 {
 155         if (inst == NULL)
 156                 return;
 157
 158         mllnode<FuncInst *> * it;
 159         for (it = entry_insts.begin();it != NULL;it = it->getNext()) {
 160                 if (inst == it->getVal())
 161                         return;
 162         }
 163
 164         entry_insts.push_back(inst);
 165 }
 166
 167 void FuncNode::function_entry_handler(thread_id_t tid)
 168 {
 169         set_marker(tid);
 170         init_inst_act_map(tid);
 171         init_local_maps(tid);
 172         init_predicate_tree_data_structure(tid);
 173 }
 174
 175 void FuncNode::function_exit_handler(thread_id_t tid)
 176 {
 177         exit_count++;
 178
 179         reset_inst_act_map(tid);
 180         reset_local_maps(tid);
 181
 182         Predicate * exit_pred = get_predicate_tree_position(tid);
 183         if (exit_pred->get_exit() == NULL) {
 184                 // Exit predicate is unset yet
 185                 exit_pred->set_exit(predicate_tree_exit);
 186         }
 187
 188         update_predicate_tree_weight(tid);
 189         reset_predicate_tree_data_structure(tid);
 190 }
 191
 192 /**
 193  * @brief Convert ModelAdtion list to FuncInst list
 194  * @param act_list A list of ModelActions
 195  */
 196 void FuncNode::update_tree(ModelAction * act)
 197 {
 198         bool should_process = act->is_read() || act->is_write();
 199         if (!should_process)
 200                 return;
 201
 202         HashTable<void *, value_set_t *, uintptr_t, 0> * write_history = history->getWriteHistory();
 203
 204         /* build inst_list from act_list for later processing */
 205 //      func_inst_list_t inst_list;
 206
 207         FuncInst * func_inst = get_inst(act);
 208         void * loc = act->get_location();
 209
 210         if (func_inst == NULL)
 211                 return;
 212
 213 //      inst_list.push_back(func_inst);
 214
 215         if (act->is_write()) {
 216                 if (!write_locations->contains(loc)) {
 217                         write_locations->add(loc);
 218                         history->update_loc_wr_func_nodes_map(loc, this);
 219                 }
 220
 221                 // Do not process writes for now
 222                 return;
 223         }
 224
 225         if (act->is_read()) {
 226
 227                 /* If func_inst may only read_from a single location, then:
 228                  *
 229                  * The first time an action reads from some location,
 230                  * import all the values that have been written to this
 231                  * location from ModelHistory and notify ModelHistory
 232                  * that this FuncNode may read from this location.
 233                  */
 234                 if (!read_locations->contains(loc) && func_inst->is_single_location()) {
 235                         read_locations->add(loc);
 236                         value_set_t * write_values = write_history->get(loc);
 237                         add_to_val_loc_map(write_values, loc);
 238                         history->update_loc_rd_func_nodes_map(loc, this);
 239                 }
 240         }
 241
 242 //      update_inst_tree(&inst_list); TODO
 243         update_predicate_tree(act);
 244
 245 //      print_predicate_tree();
 246 }
 247
 248 /**
 249  * @brief Link FuncInsts in inst_list  - add one FuncInst to another's predecessors and successors
 250  * @param inst_list A list of FuncInsts
 251  */
 252 void FuncNode::update_inst_tree(func_inst_list_t * inst_list)
 253 {
 254         if (inst_list == NULL)
 255                 return;
 256         else if (inst_list->size() == 0)
 257                 return;
 258
 259         /* start linking */
 260         sllnode<FuncInst *>* it = inst_list->begin();
 261         sllnode<FuncInst *>* prev;
 262
 263         /* add the first instruction to the list of entry insts */
 264         FuncInst * entry_inst = it->getVal();
 265         add_entry_inst(entry_inst);
 266
 267         it = it->getNext();
 268         while (it != NULL) {
 269                 prev = it->getPrev();
 270
 271                 FuncInst * prev_inst = prev->getVal();
 272                 FuncInst * curr_inst = it->getVal();
 273
 274                 prev_inst->add_succ(curr_inst);
 275                 curr_inst->add_pred(prev_inst);
 276
 277                 it = it->getNext();
 278         }
 279 }
 280
 281 void FuncNode::update_predicate_tree(ModelAction * next_act)
 282 {
 283         thread_id_t tid = next_act->get_tid();
 284         int thread_id = id_to_int(tid);
 285         int this_marker = thrd_marker[thread_id];
 286
 287         loc_inst_map_t * loc_inst_map = thrd_loc_inst_map[thread_id];
 288         inst_pred_map_t * inst_pred_map = thrd_inst_pred_map[thread_id];
 289         inst_id_map_t * inst_id_map = thrd_inst_id_map[thread_id];
 290
 291         Predicate * curr_pred = get_predicate_tree_position(tid);
 292         while (true) {
 293                 FuncInst * next_inst = get_inst(next_act);
 294                 next_inst->set_associated_read(tid, next_act->get_reads_from_value(), this_marker);
 295
 296                 Predicate * unset_predicate = NULL;
 297                 bool branch_found = follow_branch(&curr_pred, next_inst, next_act, &unset_predicate);
 298
 299                 // A branch with unset predicate expression is detected
 300                 if (!branch_found && unset_predicate != NULL) {
 301                         bool amended = amend_predicate_expr(curr_pred, next_inst, next_act);
 302                         if (amended)
 303                                 continue;
 304                         else {
 305                                 curr_pred = unset_predicate;
 306                                 branch_found = true;
 307                         }
 308                 }
 309
 310                 // Detect loops
 311                 if (!branch_found && inst_id_map->contains(next_inst)) {
 312                         FuncInst * curr_inst = curr_pred->get_func_inst();
 313                         uint32_t curr_id = inst_id_map->get(curr_inst);
 314                         uint32_t next_id = inst_id_map->get(next_inst);
 315
 316                         if (curr_id >= next_id) {
 317                                 Predicate * old_pred = inst_pred_map->get(next_inst);
 318                                 Predicate * back_pred = old_pred->get_parent();
 319
 320                                 // Add to the set of backedges
 321                                 curr_pred->add_backedge(back_pred);
 322                                 curr_pred = back_pred;
 323
 324                                 continue;
 325                         }
 326                 }
 327
 328                 // Generate new branches
 329                 if (!branch_found) {
 330                         SnapVector<struct half_pred_expr *> half_pred_expressions;
 331                         infer_predicates(next_inst, next_act, &half_pred_expressions);
 332                         generate_predicates(curr_pred, next_inst, &half_pred_expressions);
 333                         continue;
 334                 }
 335
 336                 if (next_act->is_write())
 337                         curr_pred->set_write(true);
 338
 339                 if (next_act->is_read()) {
 340                         /* Only need to store the locations of read actions */
 341                         loc_inst_map->put(next_inst->get_location(), next_inst);
 342                 }
 343
 344                 inst_pred_map->put(next_inst, curr_pred);
 345                 set_predicate_tree_position(tid, curr_pred);
 346
 347                 if (!inst_id_map->contains(next_inst))
 348                         inst_id_map->put(next_inst, inst_counter++);
 349
 350                 curr_pred->incr_expl_count();
 351                 add_predicate_to_trace(tid, curr_pred);
 352                 break;
 353         }
 354 }
 355
 356 /* Given curr_pred and next_inst, find the branch following curr_pred that
 357  * contains next_inst and the correct predicate.
 358  * @return true if branch found, false otherwise.
 359  */
 360 bool FuncNode::follow_branch(Predicate ** curr_pred, FuncInst * next_inst,
 361                                                                                                                  ModelAction * next_act, Predicate ** unset_predicate)
 362 {
 363         /* Check if a branch with func_inst and corresponding predicate exists */
 364         bool branch_found = false;
 365         thread_id_t tid = next_act->get_tid();
 366         int this_marker = thrd_marker[id_to_int(tid)];
 367
 368         ModelVector<Predicate *> * branches = (*curr_pred)->get_children();
 369         for (uint i = 0;i < branches->size();i++) {
 370                 Predicate * branch = (*branches)[i];
 371                 if (branch->get_func_inst() != next_inst)
 372                         continue;
 373
 374                 /* Check against predicate expressions */
 375                 bool predicate_correct = true;
 376                 PredExprSet * pred_expressions = branch->get_pred_expressions();
 377
 378                 /* Only read and rmw actions my have unset predicate expressions */
 379                 if (pred_expressions->getSize() == 0) {
 380                         predicate_correct = false;
 381
 382                         if (*unset_predicate == NULL)
 383                                 *unset_predicate = branch;
 384                         else
 385                                 ASSERT(false);
 386
 387                         continue;
 388                 }
 389
 390                 PredExprSetIter * pred_expr_it = pred_expressions->iterator();
 391                 while (pred_expr_it->hasNext()) {
 392                         pred_expr * pred_expression = pred_expr_it->next();
 393                         uint64_t last_read, next_read;
 394                         bool equality;
 395
 396                         switch(pred_expression->token) {
 397                         case NOPREDICATE:
 398                                 predicate_correct = true;
 399                                 break;
 400                         case EQUALITY:
 401                                 FuncInst * to_be_compared;
 402                                 to_be_compared = pred_expression->func_inst;
 403
 404                                 last_read = to_be_compared->get_associated_read(tid, this_marker);
 405                                 ASSERT(last_read != VALUE_NONE);
 406
 407                                 next_read = next_act->get_reads_from_value();
 408                                 equality = (last_read == next_read);
 409                                 if (equality != pred_expression->value)
 410                                         predicate_correct = false;
 411
 412                                 break;
 413                         case NULLITY:
 414                                 next_read = next_act->get_reads_from_value();
 415                                 // TODO: implement likely to be null
 416                                 equality = ( (void*) (next_read & 0xffffffff) == NULL);
 417                                 if (equality != pred_expression->value)
 418                                         predicate_correct = false;
 419                                 break;
 420                         default:
 421                                 predicate_correct = false;
 422                                 model_print("unkown predicate token\n");
 423                                 break;
 424                         }
 425                 }
 426
 427                 delete pred_expr_it;
 428
 429                 if (predicate_correct) {
 430                         *curr_pred = branch;
 431                         branch_found = true;
 432                         break;
 433                 }
 434         }
 435
 436         return branch_found;
 437 }
 438
 439 /* Infer predicate expressions, which are generated in FuncNode::generate_predicates */
 440 void FuncNode::infer_predicates(FuncInst * next_inst, ModelAction * next_act,
 441                                                                                                                                 SnapVector<struct half_pred_expr *> * half_pred_expressions)
 442 {
 443         void * loc = next_act->get_location();
 444         int thread_id = id_to_int(next_act->get_tid());
 445         loc_inst_map_t * loc_inst_map = thrd_loc_inst_map[thread_id];
 446
 447         if (next_inst->is_read()) {
 448                 /* read + rmw */
 449                 if ( loc_inst_map->contains(loc) ) {
 450                         FuncInst * last_inst = loc_inst_map->get(loc);
 451                         struct half_pred_expr * expression = new half_pred_expr(EQUALITY, last_inst);
 452                         half_pred_expressions->push_back(expression);
 453                 } else if ( next_inst->is_single_location() ) {
 454                         loc_set_t * loc_may_equal = loc_may_equal_map->get(loc);
 455
 456                         if (loc_may_equal != NULL) {
 457                                 loc_set_iter * loc_it = loc_may_equal->iterator();
 458                                 while (loc_it->hasNext()) {
 459                                         void * neighbor = loc_it->next();
 460                                         if (loc_inst_map->contains(neighbor)) {
 461                                                 FuncInst * last_inst = loc_inst_map->get(neighbor);
 462
 463                                                 struct half_pred_expr * expression = new half_pred_expr(EQUALITY, last_inst);
 464                                                 half_pred_expressions->push_back(expression);
 465                                         }
 466                                 }
 467
 468                                 delete loc_it;
 469                         }
 470                 } else {
 471                         // next_inst is not single location
 472                         uint64_t read_val = next_act->get_reads_from_value();
 473
 474                         // only infer NULLITY predicate when it is actually NULL.
 475                         if ( (void*)read_val == NULL) {
 476                                 struct half_pred_expr * expression = new half_pred_expr(NULLITY, NULL);
 477                                 half_pred_expressions->push_back(expression);
 478                         }
 479                 }
 480         } else {
 481                 /* Pure writes */
 482                 // TODO: do anything here?
 483         }
 484 }
 485
 486 /* Able to generate complex predicates when there are multiple predciate expressions */
 487 void FuncNode::generate_predicates(Predicate * curr_pred, FuncInst * next_inst,
 488                                                                                                                                          SnapVector<struct half_pred_expr *> * half_pred_expressions)
 489 {
 490         if (half_pred_expressions->size() == 0) {
 491                 Predicate * new_pred = new Predicate(next_inst);
 492                 curr_pred->add_child(new_pred);
 493                 new_pred->set_parent(curr_pred);
 494
 495                 /* entry predicates and predicates containing pure write actions
 496                  * have no predicate expressions */
 497                 if ( curr_pred->is_entry_predicate() )
 498                         new_pred->add_predicate_expr(NOPREDICATE, NULL, true);
 499                 else if (next_inst->is_write()) {
 500                         /* next_inst->is_write() <==> pure writes */
 501                         new_pred->add_predicate_expr(NOPREDICATE, NULL, true);
 502                 }
 503
 504                 return;
 505         }
 506
 507         SnapVector<Predicate *> predicates;
 508
 509         struct half_pred_expr * half_expr = (*half_pred_expressions)[0];
 510         predicates.push_back(new Predicate(next_inst));
 511         predicates.push_back(new Predicate(next_inst));
 512
 513         predicates[0]->add_predicate_expr(half_expr->token, half_expr->func_inst, true);
 514         predicates[1]->add_predicate_expr(half_expr->token, half_expr->func_inst, false);
 515
 516         for (uint i = 1;i < half_pred_expressions->size();i++) {
 517                 half_expr = (*half_pred_expressions)[i];
 518
 519                 uint old_size = predicates.size();
 520                 for (uint j = 0;j < old_size;j++) {
 521                         Predicate * pred = predicates[j];
 522                         Predicate * new_pred = new Predicate(next_inst);
 523                         new_pred->copy_predicate_expr(pred);
 524
 525                         pred->add_predicate_expr(half_expr->token, half_expr->func_inst, true);
 526                         new_pred->add_predicate_expr(half_expr->token, half_expr->func_inst, false);
 527
 528                         predicates.push_back(new_pred);
 529                 }
 530         }
 531
 532         for (uint i = 0;i < predicates.size();i++) {
 533                 Predicate * pred= predicates[i];
 534                 curr_pred->add_child(pred);
 535                 pred->set_parent(curr_pred);
 536         }
 537
 538         /* Free memories allocated by infer_predicate */
 539         for (uint i = 0;i < half_pred_expressions->size();i++) {
 540                 struct half_pred_expr * tmp = (*half_pred_expressions)[i];
 541                 snapshot_free(tmp);
 542         }
 543 }
 544
 545 /* Amend predicates that contain no predicate expressions. Currenlty only amend with NULLITY predicates */
 546 bool FuncNode::amend_predicate_expr(Predicate * curr_pred, FuncInst * next_inst, ModelAction * next_act)
 547 {
 548         ModelVector<Predicate *> * children = curr_pred->get_children();
 549
 550         Predicate * unset_pred = NULL;
 551         for (uint i = 0;i < children->size();i++) {
 552                 Predicate * child = (*children)[i];
 553                 if (child->get_func_inst() == next_inst) {
 554                         unset_pred = child;
 555                         break;
 556                 }
 557         }
 558
 559         uint64_t read_val = next_act->get_reads_from_value();
 560
 561         // only generate NULLITY predicate when it is actually NULL.
 562         if ( !next_inst->is_single_location() && (void*)read_val == NULL ) {
 563                 Predicate * new_pred = new Predicate(next_inst);
 564
 565                 curr_pred->add_child(new_pred);
 566                 new_pred->set_parent(curr_pred);
 567
 568                 unset_pred->add_predicate_expr(NULLITY, NULL, false);
 569                 new_pred->add_predicate_expr(NULLITY, NULL, true);
 570
 571                 return true;
 572         }
 573
 574         return false;
 575 }
 576
 577 void FuncNode::add_to_val_loc_map(uint64_t val, void * loc)
 578 {
 579         loc_set_t * locations = val_loc_map->get(val);
 580
 581         if (locations == NULL) {
 582                 locations = new loc_set_t();
 583                 val_loc_map->put(val, locations);
 584         }
 585
 586         update_loc_may_equal_map(loc, locations);
 587         locations->add(loc);
 588         // values_may_read_from->add(val);
 589 }
 590
 591 void FuncNode::add_to_val_loc_map(value_set_t * values, void * loc)
 592 {
 593         if (values == NULL)
 594                 return;
 595
 596         value_set_iter * it = values->iterator();
 597         while (it->hasNext()) {
 598                 uint64_t val = it->next();
 599                 add_to_val_loc_map(val, loc);
 600         }
 601
 602         delete it;
 603 }
 604
 605 void FuncNode::update_loc_may_equal_map(void * new_loc, loc_set_t * old_locations)
 606 {
 607         if ( old_locations->contains(new_loc) )
 608                 return;
 609
 610         loc_set_t * neighbors = loc_may_equal_map->get(new_loc);
 611
 612         if (neighbors == NULL) {
 613                 neighbors = new loc_set_t();
 614                 loc_may_equal_map->put(new_loc, neighbors);
 615         }
 616
 617         loc_set_iter * loc_it = old_locations->iterator();
 618         while (loc_it->hasNext()) {
 619                 // new_loc: { old_locations, ... }
 620                 void * member = loc_it->next();
 621                 neighbors->add(member);
 622
 623                 // for each i in old_locations, i : { new_loc, ... }
 624                 loc_set_t * _neighbors = loc_may_equal_map->get(member);
 625                 if (_neighbors == NULL) {
 626                         _neighbors = new loc_set_t();
 627                         loc_may_equal_map->put(member, _neighbors);
 628                 }
 629                 _neighbors->add(new_loc);
 630         }
 631
 632         delete loc_it;
 633 }
 634
 635 void FuncNode::set_predicate_tree_position(thread_id_t tid, Predicate * pred)
 636 {
 637         int thread_id = id_to_int(tid);
 638         ModelVector<Predicate *> * stack = thrd_predicate_tree_position[thread_id];
 639         (*stack)[stack->size() - 1] = pred;
 640 }
 641
 642 /* @return The position of a thread in a predicate tree */
 643 Predicate * FuncNode::get_predicate_tree_position(thread_id_t tid)
 644 {
 645         int thread_id = id_to_int(tid);
 646         return thrd_predicate_tree_position[thread_id]->back();
 647 }
 648
 649 void FuncNode::add_predicate_to_trace(thread_id_t tid, Predicate * pred)
 650 {
 651         int thread_id = id_to_int(tid);
 652         thrd_predicate_trace[thread_id]->back()->push_back(pred);
 653 }
 654
 655 /* Make sure elements of thrd_inst_act_map are initialized properly when threads enter functions */
 656 void FuncNode::init_inst_act_map(thread_id_t tid)
 657 {
 658         int thread_id = id_to_int(tid);
 659         SnapVector<inst_act_map_t *> * thrd_inst_act_map = history->getThrdInstActMap(func_id);
 660         uint old_size = thrd_inst_act_map->size();
 661
 662         if (old_size <= (uint) thread_id) {
 663                 uint new_size = thread_id + 1;
 664                 thrd_inst_act_map->resize(new_size);
 665
 666                 for (uint i = old_size;i < new_size;i++)
 667                         (*thrd_inst_act_map)[i] = new inst_act_map_t(128);
 668         }
 669 }
 670
 671 /* Reset elements of thrd_inst_act_map when threads exit functions */
 672 void FuncNode::reset_inst_act_map(thread_id_t tid)
 673 {
 674         int thread_id = id_to_int(tid);
 675         SnapVector<inst_act_map_t *> * thrd_inst_act_map = history->getThrdInstActMap(func_id);
 676
 677         inst_act_map_t * map = (*thrd_inst_act_map)[thread_id];
 678         map->reset();
 679 }
 680
 681 void FuncNode::update_inst_act_map(thread_id_t tid, ModelAction * read_act)
 682 {
 683         int thread_id = id_to_int(tid);
 684         SnapVector<inst_act_map_t *> * thrd_inst_act_map = history->getThrdInstActMap(func_id);
 685
 686         inst_act_map_t * map = (*thrd_inst_act_map)[thread_id];
 687         FuncInst * read_inst = get_inst(read_act);
 688         map->put(read_inst, read_act);
 689 }
 690
 691 inst_act_map_t * FuncNode::get_inst_act_map(thread_id_t tid)
 692 {
 693         int thread_id = id_to_int(tid);
 694         SnapVector<inst_act_map_t *> * thrd_inst_act_map = history->getThrdInstActMap(func_id);
 695
 696         return (*thrd_inst_act_map)[thread_id];
 697 }
 698
 699 void FuncNode::set_marker(thread_id_t tid)
 700 {
 701         marker++;
 702         uint thread_id = id_to_int(tid);
 703         for (uint i = thrd_marker.size(); i < thread_id + 1; i++) {
 704                 thrd_marker.push_back(0);
 705         }
 706
 707         thrd_marker[thread_id] = marker;
 708 }
 709
 710 /* Make sure elements of maps are initialized properly when threads enter functions */
 711 void FuncNode::init_local_maps(thread_id_t tid)
 712 {
 713         int thread_id = id_to_int(tid);
 714         uint old_size = thrd_loc_inst_map.size();
 715
 716         if (old_size <= (uint) thread_id) {
 717                 uint new_size = thread_id + 1;
 718
 719                 thrd_loc_inst_map.resize(new_size);
 720                 thrd_inst_id_map.resize(new_size);
 721                 thrd_inst_pred_map.resize(new_size);
 722
 723                 for (uint i = old_size; i < new_size; i++) {
 724                         thrd_loc_inst_map[i] = new loc_inst_map_t(128);
 725                         thrd_inst_id_map[i] = new inst_id_map_t(128);
 726                         thrd_inst_pred_map[i] = new inst_pred_map_t(128);
 727                 }
 728         }
 729 }
 730
 731 /* Reset elements of maps when threads exit functions */
 732 void FuncNode::reset_local_maps(thread_id_t tid)
 733 {
 734         int thread_id = id_to_int(tid);
 735         thrd_loc_inst_map[thread_id]->reset();
 736         thrd_inst_id_map[thread_id]->reset();
 737         thrd_inst_pred_map[thread_id]->reset();
 738 }
 739
 740 void FuncNode::init_predicate_tree_data_structure(thread_id_t tid)
 741 {
 742         int thread_id = id_to_int(tid);
 743         int old_size = thrd_predicate_tree_position.size();
 744
 745         if (old_size <= thread_id + 1) {
 746                 thrd_predicate_tree_position.resize(thread_id + 1);
 747                 thrd_predicate_trace.resize(thread_id + 1);
 748
 749                 for (int i = old_size; i < thread_id + 1; i++) {
 750                         thrd_predicate_tree_position[i] = new ModelVector<Predicate *>();
 751                         thrd_predicate_trace[i] = new ModelVector<predicate_trace_t *>();
 752                 }
 753         }
 754
 755         thrd_predicate_tree_position[thread_id]->push_back(predicate_tree_entry);
 756         thrd_predicate_trace[thread_id]->push_back(new predicate_trace_t());
 757 }
 758
 759 void FuncNode::reset_predicate_tree_data_structure(thread_id_t tid)
 760 {
 761         int thread_id = id_to_int(tid);
 762         thrd_predicate_tree_position[thread_id]->pop_back();
 763
 764         predicate_trace_t * trace = thrd_predicate_trace[thread_id]->back();
 765         delete trace;
 766         thrd_predicate_trace[thread_id]->pop_back();
 767 }
 768
 769 /* Add FuncNodes that this node may follow */
 770 void FuncNode::add_out_edge(FuncNode * other)
 771 {
 772         if ( !edge_table.contains(other) ) {
 773                 edge_table.put(other, OUT_EDGE);
 774                 out_edges.push_back(other);
 775                 return;
 776         }
 777
 778         edge_type_t edge = edge_table.get(other);
 779         if (edge == IN_EDGE) {
 780                 edge_table.put(other, BI_EDGE);
 781                 out_edges.push_back(other);
 782         }
 783 }
 784
 785 /* Compute the distance between this FuncNode and the target node.
 786  * Return -1 if the target node is unreachable or the actual distance
 787  * is greater than max_step.
 788  */
 789 int FuncNode::compute_distance(FuncNode * target, int max_step)
 790 {
 791         if (target == NULL)
 792                 return -1;
 793         else if (target == this)
 794                 return 0;
 795
 796         SnapList<FuncNode *> queue;
 797         HashTable<FuncNode *, int, uintptr_t, 0> distances(128);
 798
 799         queue.push_back(this);
 800         distances.put(this, 0);
 801
 802         while (!queue.empty()) {
 803                 FuncNode * curr = queue.front();
 804                 queue.pop_front();
 805                 int dist = distances.get(curr);
 806
 807                 if (max_step <= dist)
 808                         return -1;
 809
 810                 ModelList<FuncNode *> * outEdges = curr->get_out_edges();
 811                 mllnode<FuncNode *> * it;
 812                 for (it = outEdges->begin();it != NULL;it = it->getNext()) {
 813                         FuncNode * out_node = it->getVal();
 814
 815                         /* This node has not been visited before */
 816                         if ( !distances.contains(out_node) ) {
 817                                 if (out_node == target)
 818                                         return dist + 1;
 819
 820                                 queue.push_back(out_node);
 821                                 distances.put(out_node, dist + 1);
 822                         }
 823                 }
 824         }
 825
 826         /* Target node is unreachable */
 827         return -1;
 828 }
 829
 830 void FuncNode::add_failed_predicate(Predicate * pred)
 831 {
 832         failed_predicates.add(pred);
 833 }
 834
 835 void FuncNode::update_predicate_tree_weight(thread_id_t tid)
 836 {
 837         failed_predicates.reset();
 838
 839         predicate_trace_t * trace = thrd_predicate_trace[id_to_int(tid)]->back();
 840
 841         // Update predicate weights based on prediate trace
 842         for (mllnode<Predicate *> * rit = trace->end(); rit != NULL; rit = rit->getPrev()) {
 843                 Predicate * node = rit->getVal();
 844                 ModelVector<Predicate *> * children = node->get_children();
 845
 846                 if (children->size() == 0) {
 847                         double weight = 100.0 / sqrt(node->get_expl_count() + node->get_fail_count() + 1);
 848                         node->set_weight(weight);
 849                 } else {
 850                         double weight_sum = 0.0;
 851                         for (uint i = 0;i < children->size();i++) {
 852                                 Predicate * child = (*children)[i];
 853                                 double weight = child->get_weight();
 854                                 weight_sum += weight;
 855                         }
 856
 857                         double average_weight = (double) weight_sum / (double) children->size();
 858                         double weight = average_weight * pow(0.9, node->get_depth());
 859                         node->set_weight(weight);
 860                 }
 861         }
 862 }
 863
 864 void FuncNode::print_predicate_tree()
 865 {
 866         model_print("digraph function_%s {\n", func_name);
 867         predicate_tree_entry->print_pred_subtree();
 868         predicate_tree_exit->print_predicate();
 869         model_print("}\n");     // end of graph
 870 }